Jeanne Giovannoni, a UCLA professor whose research helped expand understanding of the categories of child abuse and how social workers, law enforcement and community members respond to them, died Dec. 17 at Santa Monica UCLA Medical Center. She was 78.

The cause was lung cancer, said Ralph Hurtado, a longtime friend.

Giovannoni was a longtime professor in UCLA's School of Social Welfare and associate vice chancellor for faculty relations until her retirement in 1993. A prolific scholar, she was best known for "Defining Child Abuse" (1979), a widely cited book co-written with UCLA colleague Rosina M. Becerra.

That book "basically changed how we define child maltreatment," said Becerra, a UCLA professor and vice provost for faculty diversity. "She pulled it apart to say that there are many ways children are maltreated."

The book drew on interviews with professionals who work with child abuse victims and their families -- including pediatricians, social workers, law enforcement and attorneys -- and analysis of 949 cases of child abuse in four California counties. The authors defined child abuse as physical or sexual mistreatment as well as neglect stemming from poverty, family dysfunction and other conditions.

They also found that each group of professionals rated the seriousness of various types of child abuse differently. Police officers, for instance, tended to focus more on parental sexual behavior, while social workers were more concerned with emotional mistreatment. Giovannoni and Becerra also discovered that cultural background influenced people's perceptions of what constituted child abuse.

Psychiatrist James S. Gordon, in a 1980 New York Times review, noted that the book was mainly of interest to scholars and child abuse investigators but that its findings about beliefs, attitudes and treatments were "of broad significance."

Giovannoni also wrote "Children of the Storm: Black Children and American Child Welfare" (with Andrew Billingsley, 1972) and "Child Abuse and Neglect: An Examination from the Perspective of Child Development Knowledge" (with Jonathan Conklin and Patty Iiyama, 1978).

Born in San Francisco on Oct. 31, 1931, Giovannoni earned a bachelor's degree in social welfare in 1953 from UC Berkeley, where she completed a master's in the same field two years later. She received a doctorate from Brandeis University in 1966.

She was an associate specialist in UC Berkeley's School of Social Welfare for three years before joining the UCLA faculty in 1969. In 1983 she was named to a newly created position of associate vice chancellor for faculty relations with duties that included affirmative action and assisting faculty members with housing and child care issues.

Giovannoni is survived by a sister, Pauline Wilson of Orinda.

A memorial service will be held Jan. 22 at the UCLA Faculty Center. Memorial donations may be sent to El Nido Family Services, 10200 Sepulveda Blvd., Suite 350, Mission Hills, CA 91345 or to Friends of the Los Angeles Philharmonic, 151 S. Grand Ave., Los Angeles, CA 90012.